Norbornene derivative and norbornene polymer obtained therefrom through ring opening polymerization

Abstract

A novel norbornene derivative represented by a general formula (1m) shown below is provided. By conducting a ring opening polymerization of this norbornene derivative, or by performing a subsequent hydrogenation following the ring opening polymerization, a ring opening polymer or a hydrogenated product thereof with an excellent low birefringence can be obtained. [wherein, at least one of R<1 >to R<4 >is a group selected from the group consisting of groups represented by a general formula (1-1) shown below and groups represented by a general formula (1-2) shown below] [wherein, at least one of R, Rand Z is a group represented by the formula -C(O)O-].

Description

[0001] The present invention relates to a precursor monomer compound for a cyclic olefin-based polymer which combines excellent transparency and a low birefringence.[0002] In addition, the present invention relates to a norbornene-based ring opening polymer which combines excellent transparency and a low birefringence.[0003] Conventionally, transparent resins are used as the materials for molded products which typically require transparency such as automobile components, illumination equipment and electrical components. Particularly in recent years, the application of these resins as optical materials, in which the optical properties are important, continues to progress. Examples of known transparent resins which can be ideally applied to such applications include polycarbonate-based resins and acrylic-based resins. However, although acrylic-based resins offer excellent transparency, they have problems in terms of heat resistance and water resistance. In contrast, polycarbonate-base...

AI Technical Summary

Benefits of technology

[0128] Of these, norbornene derivatives wherein in the general formula (1m), m=1 and n=0, and three of R.sup.1 to R.sup.4 are hydrogen atoms and the remaining one group of R.sup.1 to R.sup.4 is a group represented by either the general formula (1-1) or the general formula (1-2) produce polymers with high heat deformation resistance and low water absorption and are consequently preferred. In addition, use of either 5-(2-naphthalenecarbonyloxy)bicyclo[2.2.1]hept-2-ene or 5-(4-biphenylcarbonyloxy)bicyclo[2.2.1]hept-2-ene produces a polymer that is effective in producing molded products with excellent low birefringence.

[0129] A norbornene derivative of the present invention can be converted to a desired polymer by a ring opening polymerization, a ring opening polymerization followed by a hydrogenation reaction, an addition polymerization, a radical polymerization, a cationic polymerization or an anionic polymerization or the like. Furthermore, where necessary, copolymers can also be produced by copolymerization with an arbitrary copolymerizable compound. Polymers synthesized from a norbornene derivative of the present invention display excellent transparency, low water absorption and a low birefringence.

[0149] Of the compounds, norbornene-based monomers wherein in the general formula (1m), m=1 and n=0, and three of R.sup.1 to R.sup.4 are hydrogen atoms and the remaining one group of R.sup.1 to R.sup.4 is a group represented by either the general formula (1-1) or the general formula (1-2) described in relation to the general formula (1m) of the aforementioned norbornene derivative produce polymers with high heat resistance and low water absorption and are consequently preferred. In addition, use of either 5-(2-naphthalenecarbonyloxy)bicyclo[2.2.1]hept-2--ene or 5-(4-biphenylcarbonyloxy)bicyclo[2.2.1]hept-2-ene is effective in producing molded products with low birefringence.

[0257] 8-methyl-8-methoxycarbonyltetracyclo[4.4.0.1.sup.2,5.1.sup.7,10]-3--dodecene is particularly preferred as the production method is simple.

[0279] A variety of known additives can be added to a ring opening polymer of the present invention or a hydrogenated product thereof. Examples of such additives include phenol-based or hydroquinone-based antioxidants such as 2,6-di-t-butyl-4-methylphenol, 2,2-methylenebis(4-ethyl-6-t-butyl-phenol), 2,5-di-t-butylhydroquinone, tetrakis[methylene-3-(3,5-di-t-butyl--4-hydroxyphenyl)propionate]methane, 4,4-thiobis-(6-t-butyl-3methylphenol), 1,4-bis(4-hydroxyphenyl)cyclohexane and octadecyl-3-(3,5-di-t-butyl-4-hyd-roxyphenyl)propionate, as well as phosphorus-based antioxidants such as tris(4-methoxy-3,5-diphenyl)phosphite, tris(nonylphenyl)phosphite and tris(2,4-di-t-butylphenyl)phosphite, and by adding either one, or two or more of these antioxidants, the oxidation stability of the ring opening polymer or the hydrogenated product thereof can be improved. In addition, by adding ultraviolet absorbing agents such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone and 2,2-methylenebis[4-(1,1,3,3-tetrameth-ylbutyl)-6-[(2H-benzotriazol-2-yl)phenol]], the light resistance can be improved. Additives such as lubricants may also be added to improve the workability.

[0280] A norbornene-based polymer of the present invention displays excellent transparency, low water absorption and a low birefringence, and moreover generates a uniform retardation. As a result, a polymer of the present invention is useful within fields such as optics, and electrical and electronic materials. For example, the polymers can be ideally applied to use as molding materials for optical disks, magneto-optical disks, optical lenses (such as F.theta. lenses, pickup lenses, laser printer lenses and camera lenses), spectacle lenses, optical films or sheets (such as display films, retardation films, polarizing films, polarizing plate protective films, diffusion films, antireflective films, liquid crystal substrates, EL substrates, electronic paper substrates, touch panel substrates and PDP front plates), transparent conductive film substrates, optical fibers, light guide plates, light diffusion plates, optical cards, optical mirrors, IC, LSI and LED sealing materials.

Problems solved by technology

However, although acrylic-based resins offer excellent transparency, they have problems in terms of heat resistance and water resistance.

In contrast, polycarbonate-based resins offer superior performance to acrylic resins in terms of heat resistance and water resistance, but suffer from different problems such as a high birefringence.

Cyclic olefin-based polymers such as those described above are typically converted to products by fabrication using molding methods such as injection molding and molten extrusion molding, although with conventional cyclic olefin-based polymers, the birefringence which develops due to the polymer orientation during the molding process has not always satisfied the demanded characteristics, and as a result, the optical characteristics of the generated optical product also failed to meet the demanded characteristics.

Images